Surgical microscopes as a rule are very heavy, for which reason their stands comprise rollers so that the surgical microscopes can easily be displaced from one position to another with no need to lift them. Conversely, however, it is necessary for the surgical microscopes not to be unintentionally moved during the surgical procedure, since the success of the procedure can thereby be jeopardized. The stand bases have, for this purpose, braking systems by which the stand bases and thus the surgical microscopes can be immobilized.
A further problem that occurs with stands for surgical microscopes is that their weight and/or center of gravity change depending on position and population with additional components. In addition, surgical microscopes usually have very long-reach arms. The consequence of this is that the stand bases must be very heavy in order to prevent the surgical microscope from tipping over.
The heavy weight of the stand bases is also disadvantageous, however, since they may need to be carried when delivered, which can be ergonomically very unfavorable.
The document EP 1 026 531 B1 discloses a stand base for microscopes in which different additional weights can be selectably received in the stand base body. This has the advantage that the individual components can be individually carried upon delivery, but that secure and stable positioning is ensured thanks to the total weight achieved by reception of the additional weights. With this stand base, the additional weights are placed on a plate that is then connected to the actual stand base body via a threaded rod. It is disadvantageous in this context that this installation is quite laborious.
The stand base of the document EP 1 026 531 B1 furthermore comprises four brake blocks, each of which has associated with it an actuation element that, upon actuation, ensures that the individual brake blocks come into contact with the floor and thus enable immobilization of the stand base and prevent unintentional displacement. This braking system is disadvantageous in that for secure fastening, multiple pedals must be stepped on.
A further stand base for microscopes is known from the document EP 0 922 181 B1.